In the present disclosure, where a document, an act and/or an item of knowledge is referred to and/or discussed, then such reference and/or discussion is not an admission that the document, the act and/or the item of knowledge and/or any combination thereof was at the priority date, publicly available, known to the public, part of common general knowledge and/or otherwise constitutes prior art under the applicable statutory provisions; and/or is known to be relevant to an attempt to solve any problem with which the present disclosure is concerned with. Further, nothing is disclaimed.
A firearm, especially a military firearm, such as an M16 rifle, is often equipped with a standardized elongated rail for securely mounting a firearm capability enhancement accessory, such as an aiming device, a lighting device, a gripping device, a rangefinder, a scope, a sling, or many others. Such rail frequently comprises a T-shaped cross-section with a top of the T-shape corresponding to a top of the rail. Furthermore, such rail can be slotted transversely along a length of the rail, allowing for an indexed spacing of the accessory. Some examples of such rail include MIL-STD-1913 Picatinny, NATO Accessory Rail (STANAG 4694), or a Weaver Rail.
An accessory mount can be used to attach the accessory to the rail. Typically, the accessory mount tends to employ a multitude of screws or levers for locking the onto the transverse slots of the rail. However, the accessory mount that employs the screws often relies on relatively large frictional forces between the screws and a base of the accessory mount to remain securely fastened under a recoil of the firearm in various field conditions. To achieve this minimum torque, such accessory mount involves a separate tool to fasten the screws, which inconveniences a firearm operator by having the firearm operator carry this specific tool, which can be lost. Also, such high level of torque can cause the accessory mount to flex, which affects a point of aim of the accessory. As a result, the base made to use the screws are frequently overbuilt to resist this flex. Even if fastened with a high level of torque, the screws can eventually loosen under the recoil of the firearm, and as such, the screws often remain fastened through an externally applied threadlocking chemical. Most common commercial threadlocking chemicals function best when the screws are cleaned and dried prior to reapplication of the threadlocking chemical in case of re-installation of the accessory mount. This again inconveniences the firearm operator forcing the firearm operator to carry the threadlocking chemical and related cleaning supplies, which is cumbersome and impractical in various field conditions.
When the accessory mount employs a thumbscrew as a primary rail fastening means, drawbacks still remain. For example, such accessory mount also relies on comparatively large frictional forces between the thumbscrew and the base to remain securely fastened under the recoil of the firearm rifle and various field conditions. As the screws described above, the thumbscrew mount suffers from similar drawbacks, but in addition a head of the thumbscrew is often excessively large in order to provide an average firearm operator sufficient leverage to achieve the minimum torque needed to secure the accessory mount using only the firearm operator's hands. Therefore, such large thumbscrew head protrudes excessively from the accessory mount causing a risk of being caught on clothing, equipment, or surroundings, sometimes even impeding a proper function of the firearm. Additionally, the large thumbscrew can add to a weight of the accessory mount, which is detrimental to the firearm operator's comfort and ability to quickly maneuver the firearm. Furthermore, experience has shown that even a tightly fastened thumbscrew is likely to loosen without some secondary means of securing the thumbscrew from loosening under vibration of the firearm's recoil, such as s threadlocking chemical or a secondary set screw. Both of these solutions are cumbersome and impractical in various field conditions.
Although throw-lever actuated locking mechanisms exist, such mechanisms suffer from having levers which protrude from the accessory mount. Such lever can easily get caught on clothing, gear, and surroundings. Further, such lever and an associated ancillary lever locking mechanism add considerable weight, size, or complexity by involving a large number of components with the accessory mount, while introducing non-intuitive operating procedures to unlock and lock the lever. Like a high torque screw accessory mount, as described above, the lever mount can introduce high levels of stress into the base, which can cause the base to flex and potentially shift the point of aim of the accessory. Unlike screw or thumbscrew type accessory mounts, which can use a shaft of the screw or thumbscrew to act as a recoil lug, a lever actuated accessory mount requires a distinct shear lug to be machined or otherwise formed into the base in order to securely lock the accessory mount within the transverse slots of the rail. Such state of being further adds cost, and weight to the accessory mount.